Station identifier



Dec. 11, WAH T STATION IDENTIFIER Filed April 27, 1944 INYENTOR HAROLD A. WAHLSTRAND M346 ATTOBNEY.

Patented Dec. 11, 1945 STATION IDENTIFIER Harold A. Wahlstrand, Chicago, Ill., assignor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application April 27, 1944, Serial No. 533,023

16 Claims.

This invention relates to printing telegraph apparatus and more particularly to automatic station identification apparatus used in combination with printing telegraph apparatus.

In many printing telegraph systems and networks there are a plurality of remote stations on a loop circuit which communicate telegraphically with a, central station at predetermined times in a predetermined sequence. Inasmuch as there are a number of such remote stations, some of which sometimes do not have messages to communicate to the central station, it is desirable to provide means whereby the incoming message at the central station may be identified as to its origin.

Accordingly, an object of this invention is to provide automatic station identification apparatus which will communicate to a central station the origin of the incoming message.

Another object of this invention is to provide automatic station identification equipment in combination with a telegraph transmitter in such a manner that the identification signals will invariably precede the telegraphic message.

A further object of this invention is to provide means whereby the telegraph transmitting apparatus will be held unoperative as to the transmission of messages for a period of time during 1 transmitting unit, and means to prevent operation of the tape sensing unit during the period of operation of the identification cam drum, thereafter allowing operation of the tape sensing unit to transmit the message code signals over the transmitting unit.

A more detailed understanding of the invention may be had from the following description with reference to the accompanying schematic drawmg.

The tape sensing unit and transmitting unit are described only to an extent necessary to understand the present invention and may be understood more fully by referring to Bulletin No. 141, issued in March, 1942, by the Ieletype Corporation, Chicago, Illinois, wherein they are described substantially.

The tape sensing unit which is designated generally by the numeral l l receives the tape l2 from a tape perforating apparatus 13, many types of which are well known in the art.

The tape I2 known in the art. pivoted on a shaft 28, each having leftwardly passes over a guide roller 14, moves downwardly and under a taut-tape roller it which will be mentioned later, and forms in a loop and passes over a guide roller ll which is in a horizontal plane with the previously mentioned guide roller 14. The taut-tape roller 16 is supported in two slotted guides i8 and has an outwardly extending arm 19 which controls an electrical contact pair 2 l, as will be hereinafter described; The tape l2 then passes over a sprocket wheel 22 which is fastened securely to a shaft 23 and which has teeth thereon to engage in the perforated feed holes in the tape I 2 and thus feed the tape through the sensing mechanism. The shaft 23 has a ratchet 24 secured to one end thereof by means of which the tape feed operation is effected, as will be later explained.

Immediately after the tape [2 passes from the sprocket 22 it passes over a set of five contact levers 26 each of which has a tape sensing pin 2'! extending upwardly from its forward end. The tape sensing pins 21 are adapted under certain operating conditions to probe upwardly to sense the tape in order to determine whether the particular code signal being sensed is comprised of marking or spacing impulses, in a manner well The contact levers 26 are extending arms 29 and downwardly extending arms 3!. Each of the contact levers 26 has an individual spring 32 which is connected to the leftwardly extending arm 29 and tends to rotate the contact levers 26 in a counterclockwise direction about the pivot shaft 28, as viewed in the drawing. Each of the leftwardly extending arms 29 of the contact levers 26 has a slot 33 formed at its extremity.

Positioned approximately below the shaft 28 is [a contact lever bail 34 which is immediately to the right of the downwardly extending arms 3| of the contact levers 26 and extends across all of the arms 3|. The bail 34, mounted pivotally on a pivot shaft 36, has a downwardly extending lug 31.

Also mounted :pivotally on the shaft 28 is a feed lever 38 which has a leftwardly extending arm 39 and a downwardly extending arm 4|. A spring 42 is connected to the arm 39 and tends to pivot the feed lever 38 in a counterclockwise pawl 43 is situated adjacent to the ratchet wheel 24 and cooperates therewith during certain operating conditions to cause the tape I2 to be fed forwardly. The bail 34, described previously as extending across the downwardly extending arms 3| of the contact levers 26, also extends across the downwardly extending arm ll of the feed lever 38.

Situated immediately to the left of the slots 33 at the extremities of the rearwardly extending arms 29 of the contact levers 26 are a series of five contact arms 46. one individual to each contact arm 26, which are mounted pivotally on an electrical conductor shaft 41. The right-hand ends of the contact arms 46 which cooperate withthe slots 33 are insulated, whereas the remaining portions of the contact arms are electrical conductors. The opposite ends of the contact arms 46, remote from the insulated portion cooperating with the slots 33, form a movable tongue to cooperate with an upper electrical spring contact 48 or a lower electrical spring contact 49. Thus, depending upon the position of the contact arms 46 an electrical contact will be made with either the upper spring contact 48 or the lower spring contact 49, in a manner to be hereinafter described. 7

The transmitting unit comprises a commutator 5| formed with five equal size segments 52 thereon, each of which is assigned to one impulse of the well-known Baudot five unit code. Two other segments are provided on the commutator face other than the five segments 52, one of which, 53, is assigned to the stop interval while the other, 54, is assigned to the start interval. Thus, the transmitting apparatus is of the start-stop type, the operation of which is well known. A collector ring 56 is provided which is formed in a complete circle concentric to the ring of segments and which is electrically connected successively therewith by means of a distributor brush 5'! which is mounted securely to a distributor shaft 58 to rotate therewith.

A motor 59 is provided having a worm gear 6| on the motor shaft which cooperates with and continuously drives a gear wheel 62 positioned an electrical circuit from an alternating current source to drive the motor 59; obviously, a direct current source may also be used.

Positioned securely to the distributor shaft 58 is a cam '66 which has a stop lug 6'1 extending therefrom. The stop lug 61 engages, during cer-' tain periods of operation, with the end of a stop arm 68 which is pivotally mounted on a shaft 69 and which is normally biased in a counterclockwise direction into engagement with the stop lug The opposite end 61 by means of a spring 'II. of the stop arm 68 forms an armature for a magnet I2.

An operating cam I3 is also secured to the distributor shaft 56 and cooperates with a cam follower roller I4 which forms one end of a transmitter operating lever I6 pivotally mounted on" a stud TI. The opposite end of the transmitter operating lever '16 has an upwardly extending portion I 8 which has an adjusting screw 19 passing therethrough. The adjusting screw 19 is immediately adjacent to the downwardly extending arm 31 of the contact lever bail 3'4 which was previously mentioned, and cooperates therewith in a manner later to be explained. The adjusting screw I9 has been provided so that an adjustment can be made between the downwardly extending arm 31 of the bail 34 and the upwardly extending stantially described in the above-mentioned bulletin issued by the Teletype Corporation. However, it is necessary to describe them herein inasmuch as they form part of the present invention, as will now be set forth.

1 Adjacent the up-turned end 18 of the transmitter operating lever I6 is blocking lever designated generally as BI which is pivotally mounted armature for a magnet 89. Located adjacent the arm 81 and under the control thereof is a contact pair 9|. A latching lever 92 having a hook 63 at its one extremity which is provided to engage the notch 88 in the arm 81 of the blocking lever 8| under certain conditions is pivotally mounted on a stud 9d and biased in a clockwise direction, as viewed in the drawing, by means of a spring 96. The lever 92 acts as an armature for a, magnet 91.

Alsosecured to the distributor shaft 58 is a cam IOI. which controls a follower roller I02 secured to a lever I03 pivoted on a stud I04. The lever I03 which has a notch I06 at its opposite end, is normally biased in a counterclockwise direction by means of a spring I0'I. A pawl I08 ispivotally mounted to shaft I03 at I09 and is normally urged in a counterclockwise direction by means of a pring II I. Adjacent the notched end I06 of the lever I03 is 'a lever II2 which has a locking lug II3 thereon to cooperate with the notch I06 and which'is pivotally mounted on a pivot shaft I I4 and normally urged in a counterclockwise direction by means of a spring I16. The lever H2 forms the armature for a magnet II'I.

Adjacent the pawl I08 is a ratchet wheel IIB which is mounted toward the end of a shaft I I9. The shaft H9 is journaled rotatably in bearings, which are not shown, and has a cam sleeve I2I securely fastened thereto. The cam sleeve I2I is formed with a series of five cams I22 thereon which correspond with the five impulses of a standard five unit permutation code and a sixth cam I23 which acts for a special purpose as will be later described. Each of the cams I22 controls an individual adjacent electrical contact pair I24 which is normally in an open condition whileth'e' sixth or special cam I23 controls an electrical contact arm I26 which operates two electrical contact pairs I2! and I28.

The cams I22 are formed with depressions in their periphery in a predetermined order so as to close the contact pairs I24 in a manner such as to transmit predetermined station identification permutation code signals. In this manner it is possible to send identification signals such as for instance, the letters CHI designating Chicago, or signals which may be necessary to condition the central station printer for receiving these identification signals, such, for instance, as carriage return, letters shift, figures shift, etc. De pending upon the number of depressions in the cam periphery and the number of teeth on the ratchet II8, it is possible to send out as many station identification signals as desired. A typical station identification signal might comprise carriage rturn, letters shift, a three letter identification such as CHI, and a space signal.

The operation of the station identification apparatus and its automatic cooperation with the tape sensing and transmitting apparatus, and the electrical circuits thereof, will now be described.

Upon a manual closing of the switch 64 a'circuit is completed from the current source to cause the operation of the motor 59 which results in rotation of the worm gear 6| on the motor shaft and a consequent rotation of the gear 62 about the distributor shaft 58. However, at this time the distributor shaft 58 will not rotate, inasmuch as the stop arm 68 is engaging the stop lug 61 and preventin rotation thereof. Such nonrotation of the distributor shaft 58 is possible because of the friction clutch 63. The distributor brush 51 is at this point on the stop segment 53 of the commutator which is customary in start-stop telegraphy. Upon the manual closure of switch I29, assuming that there is sufiicient tape I2 in the loo-p to allow the taut-tape roller I6 to be in a downward position with its arm I9 closing the contact pair 2|, potential will be supplied from grounded battery I3| through the switch I29, through the contact pair 2| which is closed, over conductor I32 and through the winding of relay I33 to ground. Inasmuch as relay I33 is of the slow to operate type, its armature I 34 will not be attracted immediately but instead an electrical circuit will also be established from grounded battery I3I through switch I29, through contact pair 2|, over conductor I32, through armature I 34, over conductor I36, and through the winding of magnet 89 to ground.

The energization of magnet 89 immediately causes its armature, which comprises arm 81 of blocking lever 8|, to b attracted resulting in a counterclockwise movement of the blocking lever 8| to a position whereat its blocking arm 84 will be positioned immediately in front of the upturned end I8 of the transmitter operating lever I6. The blocking lever 8| will be held in this position, inasmuch as the lever 92 will move in a clockwise direction under the urging of its spring 96 whereat its hooked end 93 will engage the notch 88 in the end of the arm 8! of the blocking lever 8|. This is possible, inasmuch as magnet 91 is ole-energized at this time and is not therefore attracting its armature which is lever 92.

As the slow to operate relay I33 has not yet become energized to attract its armature I34, no circuit has been stablished for initiating rotation of the distributor shaft 58. Thus, the brush arm 51 is positioned on the stop segment 53 and the apex of cam I3 is presented to the follower roller I4. In this position the transmitter operating lever I6 is held in its extreme counterclockwise position with its set screw I9 engaging the contact bail 34 and pivoting it about the shaft 36 to cause its upper portion to engage the downwardly extending arms 3| of the contact levers 26 and the arm 4| of the feed lever 38, pivoting them in a clockwise direction about the haft 28. The result of this is to hold the sensing pins 2! out of tape sensing position and to prevent the tape feed operation which is dependent on the pawl 43 moving upwardly with respect to the ratchet 24, engaging a tooth, and thereafter moving downwardly to step the ratchet at predetermined times. As the transmission of message signals is dependent upon the pins 2! sensing the tape successively upon a new section being presented thereto through intermittent tape feed, no'mesestablished from the grounded battery sage transmission will occur as longes the blocking arm 84 engages the upwardly extended portion I8 of the transmitteroperating lever I6, thus preventing the lever from following the nadir of the cam I3 and releasing the contact bail 34; any such release of the bai1 34 would allow the contact levers 26 and the feed lever 38, under the action of their springs 32 and 42, respectively, to operate the tape sensing apparatus II in a normal manner.

As previously mentioned, the relay I33 is of the slow to operate type and immediately after the energization of magnet 89 and its causing the blocking lever 8| to be moved in a counterclockwise direction, the armature -|34 is attracted to the relay I33. This results in potential no longer being supplied to the magnet 89, resulting in its de-energization. However, the blocking lever 8| will not be able to move back to its extreme clockwise position because, as previously mentioned, the lever 92 through its hooked end 93 cooperating with the notch 88 holds the blocking lever 8| in its locking position.

The movement of blocking lever 8| to its counterclockwise position results in the closure of the contact pair 9| which allows an electrical circuit to be established from grounded batter-y I38, through closed contact pair 9|, over conductor I39, over conductor I40, and through the winding of magnet III to ground. The magnet II! will immediately become energized, resulting in its armature lever I I2 being attracted thus allowing the blocking lug M3 to move from the notch I06 of the cam follower lever I03. The magnet III remains energized during the trans-- mission of the station identification signals.

As a result of the slow acting relay I33 attracting its armature I34, an electrical circuit is I3I, through the switch I29, closed contact pair 2|, conductor I32, armature I34, conductor I3I, the winding of magnet I2 to ground. The energization of magnet I2 results in its armature stop arm 68 being attracted and removed from blocking position with respect to stop lug 61 of cam 66. The rotation of the distributor shaft 58 does not affect transmitter operating lever I6, through cam I3, as the lever I6 is locked out by the blocking lever 8 I.

As the distributor shaft 58 rotates, its cam IOI moves from rest position with its apex against the roller I02 which results in the lever I03 moving in a counterclockwise direction following the nadir of the cam I0| and the pawl I08 engaging a tooth of the ratchet I I8 and causing ro tation of the shaft 9 and the cam sleeve I2I secured thereto for a distance of one tooth. The timing of the stepping of the shaft I I9, through the movement of ratchet II8 under the action of the pawl I08, is such that the shaft H9 and the cam sleeve |2I thereon will be stepped to its next position by the time that the distributor brush 51 sweeps over'the stop and start segments but before the first of the impulse segments 52 has been traversed. The result of the one step rotation of cam sleeve |2| is to present cam dopressions to certain of the spring contacts con-- trolling the contact pairs I24, according to a predetermined coding. Those of the contact springs of contact pairs I24 which are allowed to enter depressions in the cam sleeve I22 cause their corresponding contact pairs |24 to close and establish electrical circuits from a common ground through the closed contact pairs I24, over conductors |4I to contact points I42 associated with the-upperspring contacts 48;: over the conductors I43; and to thesegments 52c0rresponding to the particular code. At the. time that the distributor brush. 5'! traverses the segment 52 to which the electrical circuit has just been traced, the circuit will be further completed through brush 51, collector ring 56, and over line conductor I44 to the central station where battery is supplied. Inasmuch as no further stepping will occur until such time as the brush arm 51 traverses all of the segments 52 and returns to the stop segment 53, the cam sleeve I2! will remain stationary for thisperiod of time. Thus, it is assured that any of the contact pairs I24 which have been closed will remain so through the time that the brush arm 51 sweeps over the corresponding segment 52. As the distributor brush 51 reaches the stop segment 53 the cam IOI will present its apex to cam follower roller I02 which results in the cam follower lever I03 moving in a clockwise direction with its pawl I08 moving to the next tooth in the ratchet H8. At the time that the distributor brush 51 reaches the end of the start contact pairs I24, which results in certain of these contact pairs being closed by the movement of their spring lever within the depression in the cam. Thus, a circuit is established as previously traced to the line conductor I44. This results in a second station identification code signal being transmitted over the line conductor The operation which has just been described will recur according to the number of station identification signals which it is desired to transmit over the line conductor I44, depending upon the number of teeth in the ratchet wheel H8 and the number of codings in the cams I22.

When the shaft H9 and the cam sleeve I2I have been positioned at a point whereat the final station identification signal will be transmitted over the line conductor I44, the special cam I23 is positioned with its depression presented to the spring lever I26. The result of the spring lever I26 entering the depression in the cam I23 is to cause the electrical contact pairs I21 and I28 to close. The closure of the electrical contact pair I28 results in grounded battery I46 being supplied over an electrical circuit consisting of contact pair I28 and conductor I41. However, at this time no complete electrical circuit will be established as the follower lever I03 will be following the nadir of the cam IEII which results in the spring arm I48 following the follower lever I03, due to its inherent resilience, thus causing the contact pair I49 to be opened.

An electrical circuit is established through grounded battery I46, contact pair I21, over line conductor I46, and through the winding of magnet I H to ground. It is to be noted that magnet II1 was energized, as previously mentioned, as a result of the movement of the blocking lever 8| to its blocking position resulting in the closing of the contact pair 9I. Therefore, the rea sonfor the closure of the contact pair I 21 to supply battery to'the winding of magnet II1 will be apparent upon the next operation to be described.

When the distributor shaft 58 completes the rotation during which the last station identification signal was transmitted, and at the time that the distributor brush 51 reaches the stop segment 53, the apex of the cam. IIlI will be presented to the cam follower roller I02. The result of this is to cause the follower. lever' I03 to be moved in a clockwise direction, thereby causing the spring lever I48 to close the contact pair I49. As previously mentioned, an electrical potential has been supplied to the point of the open contact pair I49 from grounded battery I46, contact pair I28, and conductor I41. The circuit, is now established from this point throughthe con.- tact pair I49, over conductor I51, and through the winding of magnet 91 to ground- The energization of magnet 91 causes the locking lever 92 to be attracted which results in its hooked end 93 being removed from engagement with the notch 88 in the arm 81 of the locking lever 8|. Inasmuch as the magnet 89 is no longer energized and has not been since immediately after the very start of operation of the apparatus when the slow to operate relay I33 attracted armature 34, the blocking lever 8| is now free to move under the urging of its spring 83 to its normal clockwise limit against the stop 86.. This results in its blocking arm 84 moving from. blocking engagement with the upturned portion 18 of. the transmitter operating lever 16, which leaves the operating lever 16 to operate in a normal man.- ner with respect to the cam 13 and the bail 34.

A second result of the movement of blocking lever 8I is to cause the contact pair 9| to be opened, thus breaking the electrical circuit over conductor I39 that had previously energized the magnet H1. However, as already mentioned, a second electrical circuit for the energization of the magnet I I1 had been traced through grounded battery I46, closed contact pair I21, and the winding of the magnet to ground. As a result, magnet I I1 remains energized, thus still attracting its armature II2 thereto. The necessity for causing the magnet I I1 to be energized is to allow the cam sleeve I2I to be again stepped thereby positioning it in readiness for another transmittal of station identification signals. As a result of the continued energization of. magnet III, the continued movement of distributor shaft 58 results in the cam I0! causing the cam follower lever I03 to once again move in a clockwise direction, thereby resulting in the pawl I08 moving up another tooth on the ratchet II8. As the distributor brush 51 moves to its start segment the apex of cam I0! will ,no longer be presented to the cam follower roller I02 and the cam follower lever I03 will again move in a counterclockwise direction. This results in the shaft I I9 and the cam sleeve I 2I being stepped another step to a point whereat all of the contact pairs I24 and the contact leverv I26 will be engaged with the periphery of the cams I22 and I23 and will not enter any depressions in the cams. The failure of any of the contact pairs I 24 to close results in no electrical circuit being established through the contact points I42 and eventually over the line conductor I44. However, at this point, inasmuch as the blocking lever 8| is no longer in blocked position with respect to the transmitter operating lever 16 the tape sensing pins 21 will be presented to the first line of perforated tape resulting in the selected contact levers 26 moving to a counterclockwise position if any of the pins sense holes thereabove, thereby resulting in their notched ends 33 causing the arms 46 to be pivoted in a clockwise direction against the upper spring contact 48. The result of such a movement of any of the spring contacts 48 is to establish an electrical circuit from ground, over electrical conductor shaft 41, through electrical conductor. arms 46, through the upper contacts 48, through the contact points I42, and over the conductors I43 to the intelligence or code impulse segments 52 of the commutator Thereafter, as the brush 51 connects the respective segments successively with the collector ring 58, marking impulses will be transmitted corresponding to the selected pins over the line conductor I44 as there is battery at the remote station completing the electrical circuit. Those pins 21 which did not enter perforations cause the contact 1evers 26 to be so positioned that the arms 45 engage the lower spring contacts 49. As these are not connected electrically they correspond to spacing impulses.

As a result of the final step of the cam sleeve I2I, the cam I23 will be moved to a position whereat its single depression will not be presented to the contact lever I26, thus resulting in the contact pairs I2! and I28 being opened, as previously mentioned. The result of the opening of the contact pair I21 is to remove grounded battery I46 from the electrical circuit which caused the energization of the magnet II'I. Upon the de-energization of the magnet N7, the armature H2 will no longer be attracted and will be allowed to move to its normal counterclockwise position under the urging of its spring H6 whereat its tooth H3 will engage the notch H16 in the cam follower lever 33 and prevent its operation. This results in no further stepping of the cam sleeve I2I. Likewise, battery will be removed from the electrical circuit which caused the energization of magnet 97. However, it is no longer necessary to hold the magnet 91 energized, inasmuch as the blocking lever 8| has already moved to its clockwise position, free from its blocking position with respect to the operating lever IE, and thus the lever 92 which forms the armature of magnet 91 can no longer hold the locking lever 83 in its blocking position.-

Thus, the complete station identification signal has been automatically transmitted over the line conductor I44 upon the closure of the switch I29 which causes the apparatus to come into operation. At the expiration of the transmission of the station identification signals, the station identificationapparatus is automatically disabled and the sensing apparatus is now free to operate to transmit message signals from the tape sensing apparatus II, through the conductors I43, over the commutator segments 52 and over the line conductor I44.

It is to be noted that in the event that the taut-tape roll It should be moved upwardly due to a lack of prepared tape, etc., the arm I9 will no longer exert pressure on the contact pair 2| and it will open. This will result in the stopping of message transmission by the Opening of an electrical circuit, in a manner well known in the art. Upon an adequate supply of perforated tape, or the trouble present being overcome, the roll It will move downward and the contact pair 2| will be again closed. This will result in an electrical circuit' being established which will cause the station identification equipment to operate, as described above, even though transmission may have been halted in the middle of a message. After the station identification signals are transmitted, normal message transmission will be resumed.

Although a specific embodiment of the invention has been shown and described it will be understood that this embodiment is only illustrative and that various modifications may be made therein Without departing from the scope and spirit of this invention.

What is claimed is:

1. In combination, a tape sensing device including means to sense the tape and means to feed the tape, a bail controlling said tape sensing and said tape feeding means, means to operate said bail, means to 0100K the operation or said ball operating means, .said blocking means incluoing a blocking lever under the COIltI'Ol of a magnet, "whereby said ball will not be operated to cause the operation of said tape sensing device, and means to latch said blocking iever in its blocking position.

2. in combination, a tape sensing device including means to sense the tape and means to Ieed the tape, a bail controlling said tape sensing and sa d tape Ieeuing means, means to operate said ball, means to block the opeiation or said ball operating means, said blocking means including a blocking lever under the Cullbl'ULUJi a magnet, whereby said can will not be opeiated to cause the operation or said tape sensing device, and means to latch said blocking lever in its operated position, said latching means includin a iatehing lever under the control or a magnet.

5. 1.11 a tape tiaiisiliittei', insane; to sense a tape, means to transmit ermutation code signais according to tile setting OI 521,111. ta e sensmg means, 111681115 BO auUUu13iIilU'di1ly DLUUK said.

tape sensing means u on tile initiation or transmission, and means to iiivariaoiy transmit predetermined station identification code signals during tile intervai that said ta e sensing means are blocked.

4. In a tape transmitter, means to sense a tape, means to transmit permutation code signals according to the setting of said tape sensing means, means to automatically blOCK said tape sensing means upon the initiation or transmission, means to invariably transmit predetermined station identincation code signals during the interval that said tape sensing means are blocked,.

and means under the control of said station identification.transmitting means to remove said blocking means after said predetermined station identincation signals have been transmitted whereby code signals under the control of said tape may be transmitted. I

5. In a tape transmitter, means to sense a tape, means to transmit permutation code signals according to the setting of said tape sensing means, means to automatically block said tape sensing means upon the initiation of transmission, means to invariably transmit predetermined station identification code signals during the interval that said tape sensing means are blocked, and means under the control of said station identification transmitting means to remove said blocking means and to disable said station identification signal transmitting means after said predetermined station identification signals have been transmitted whereby code signals under the control of said tape may be transmitted.

6. In a tape transmitter, means to sense a tape, means to transmit code signals according to the setting of said tape sensing means including a segmented commutator, a distributor shaft, a

brush arm secured to said distributor shaft for rotation therewith and cooperating with said segmented commutator to transmit code signals over a line conductor, means to automatically block said tape sensing means upon the initiation of transmission, a cam distributor drum coded according to predetermined'station identification signals, means 'to rotate said cam distributor drum in a step by step manner under the control of a cam on said distributor shaft, and means to transmit said station'identification signals to said line conductor including said'segme'nted commutatorand saidbrush arm.

'7. In a 'tapetransmitter, means to sense a 'tapegmeafis to transmit permutation code sign'alsaccording to the setting of said tape sens- 'ing means'including'a segmented'commutator, a

j distributor shaft, a brush arm secured to said distributor shaft "for rotation therewith and cooperating with said segmented commutator to transmit code signals over a line conductor,

' means to automatically "loloc'k said tape 'sensing means upon the initiation of transmission, a cam distributor drum coded according to predeter- "mined station identification signals, means to rotate said cam distributor drum in a step by step'manne'r under the controlof a cam on'said distributor shaft, means to'transmit said'station identification'signals to said line conductor including said segmented commutator and said brush-arm,'and means under the'control of said station identification transmitting'means to remove saidblockingmean's andto'disable said cam distributor drum rotating means after said predetermined station identification signals have been transmitted whereby'permutation code signals under the control of said'tapemay'be transmitted.

'8. In 'a tape transmitter, a segmented commutator, a brush 'arm, tape sensing means, 'means'to' transmit code signals under the control of said tape through said segmented commutator and brush arm over a line conductoiymeans to block said tape sensing -rneans; a camdistributor dr-um coded according to predetermined station identification signals, and mean-s to transmit said station identification signals under the control -of said cam distributor --drum"through--said segbrush arm over said line conductor during the interval that said tape sensing means are blocked, and means under the control of said station identification transmitting means to re- -move said blocking means after said predetermined station identification signals have been transmitted. 1

,10. In a tape transmitter, means to sense a tape, means to transmit permutation code signals according to the setting of said tape sensing means, a lever under the control of a magnet to automatically block said tape sensing means upon the initiation of transmission, and means to invariably transmit predetermined station identification code signals during the interval that said tape sensing means are blocked; 7

11. In a tape transmitter, means to sense 'a tape, means to transmit permutation code signals according to the setting of said tape sensing means, a blockin lever operating to automatically block said tape sensing means upon the initiation of transmission, a locking lever under the control of arnagnet to lock said blocking lever in its blocking position when said magnet is deenergized, and means to invariably transmit predetermined station identification permutation code signals during the interval that said tape sensing means are blocked.

. 12. In a tape transmitter, means to sense a tape, means to transmit, code signals according to the setting of said tape sensing means, 'ablocking lever under the control of a magnet to automatically block said tape sensing means upon the initiation of transmission, a locking lever under the control of a second magnet to lock said blockin lever in its blocking position when-said second magnet is de-energized, means to invariably transmit predetermined station identification code signals during the interval that said tape sensing means are blocked, and means under the control of said station identification transmission means to cause the energization of said magnet associated with said locking lever whereby said locking lever is removed from its locking position With respect to said blocking lever and said blocking lever is removed'from its blocking 'position with respect to saidtape sensing means.

13. In combination, a first transmitting device, I

a second transmitting device, a distributor common to said devices and operatively associated therewith, means to initiate transmission under the control of one of said devices, and means to from said tape controlled device pending'completion of transmissio-nfrom said cam controlled device.

15. In combination, a first means adapted to transmit a variable message, a second means adapted to transmit an invariable message, a dis- 'tributor common to both said means and operatively associated thereto means to initiate transmission under the control of said second means, and 'means controlled by said secondmeans to defer transmission from said first means pending completion of transmission from said second means.

16. In combination, a tape controlled transmitting device, a camcontrolled transmitting device,

a brush type distributor'common to'said devices and operatively associated thereto, means to initiate transmission under the control of. said'cam controlled device, and means'controlled'by said cam controlled device to defer transmission from said tape controlled device pending completion of transmission from said camcontrolled device and thereafter to prevent operation of said cam controlled transmitting device during operation of said tape controlled transmitting device.

HAROLD A. WAHLS'I'RAND. 

